fix: avoid Alpine SVG template rendering errors in cost charts

[lc-soft]

Summary

This PR fixes chart rendering issues caused by Alpine directives inside SVG templates. In the analytics cost dashboard, SVG-based donut and bar charts could fail to render correctly (including runtime expression/import errors), which resulted in broken or incomplete chart visuals.

Changes

• Replaced SVG <template x-for> loops with x-html-based rendering for chart segments/bars.
• Added JS helper functions to generate SVG markup for donut and daily bar charts.
• Preserved existing chart behavior and data sources (colors, labels, tooltips, percentages, totals).
• Added XML escaping for generated SVG text/attributes to improve rendering safety and stability.

Testing

• cargo clippy --workspace --all-targets -- -D warnings passes
• cargo test --workspace passes
• Live integration tested (if applicable)

Security

• No new unsafe code
• No secrets or API keys in diff
• User input validated at boundaries